Visiting leaders should not be put in a position where their dignity was at risk, Acting Prime Minister Bill English says.

His comments followed Prime Minister John Key telling NZPA yesterday Parliament's security was likely to be tightened after the scuffle on Friday when Chinese vice-president Xi Jinping arrived.

Green Party co-leader Russel Norman was pushed by Chinese officials who tried to put an umbrella over him to hide a Tibetan flag he was waving.

The flag was pulled from his hands, although he managed to retrieve it and accuse the Chinese of trying to suppress freedom of speech in New Zealand.

Mr Key apologised to the delegation for the incident, and last night told NZPA the issue had nothing to do with freedom of speech.

He said he apologised for the failure to provide proper security for the vice-president.

"It's my intention...to take the matter up with Diplomatic Protection, the Ministry of Foreign Affairs and Trade and with the Speaker's office because I think it's unacceptable that a dignitary of that level can't enter the building without their integrity being compromised," he said.

"In my view we will need to go and review our procedures and protocols."

Mr Key said a balance had to be found so visiting leaders could enter and leave the building without their "close space and their integrity" being challenged.

Dr Norman yesterday accused Mr Key of making a "degrading" apology and called on him to stand up for democracy and free speech.

Mr English this morning said the Government was not trying to suppress MPs freedom of speech and that Dr Norman had misused his privileges to get closer to the vice president than a member of the public could.

"An MP does not have a right to harass visitors from overseas in a way that's unacceptable. You could argue that if security had no idea who he was they might have been more assertive with him than they were."

Mr English said the Government wanted to make sure visiting dignitaries were not "put in a position where they can be physically harassed".

He said their physical security had to be protected but then in subsequent comments also said their dignity had to also be guarded.

"We need to make sure that visitors that come to New Zealand know that their dignity can be protected including when they are in the grounds of Parliament," he said.

Mr Key would not expect to be harassed by politicians when visiting other Parliaments.

Labour leader Phil Goff said there mistakes on both sides.

"The Chinese security guard had no right to seize the flag from Russel Norman. There is an absolute right of peaceful protest in this country that we must uphold."

"Did Russel Norman behave with the dignity you might have expected of an MP? I think he might have learned from (former Greens leader) Rod Donald's lesson of standing back, giving a bit of space, making the point, but not being confrontational."

Dr Norman was following Mr Donald's former lone protest during a Chinese delegation visit.

Mr Goff said there needed to be a clear protocol allowing peaceful protest but at the same time giving space and dignity to visitors.

He said there was some confusion which could have been avoided on Friday.

"A quiet word beforehand between Russel Norman and the diplomatic police could have set a situation where a protest could have been made without the incident occurring."